1. Field of the Invention
The present invention relates to a circuit board provided to a marking material receptacle that houses a marking material for print.
2. Related Art
In recent years, there has been developed ink cartridges of a type equipped with a circuit board that has a storage device for storing data relating to the ink contained in the ink cartridge. Such circuit boards are equipped with terminals for receiving power, data for storage, etc. from a printer, or for sending stored data to a printer.
The following description of a conventional terminal arrangement makes reference to FIG. 12. Circuit board 500 has a first terminal row with a ground terminal 510 in its center, a data I/O terminal 520 to a first side thereof, and a read/write signal terminal 530 to a second side thereof; and a second terminal row, located above the first terminal row, with a power terminal 550 in its center, a clock signal terminal 540 to a first side thereof, and a chip select signal terminal 560 to a second side thereof.
Printer 580 is provided with contact pins 570 corresponding to each of these terminals 510–560; when the ink cartridge is installed in the mounting portion of the printer, terminals 510–560 come into contact with the corresponding contact pins 570 to enable power, data, etc. to be exchanged between the circuit board 500 and the printer 580. The ground terminal 510 is used to allow the printer to determine if the ink cartridge is correctly installed; ink cartridge installation is detected by sensing contact (electrical continuity) between the ground terminal pin of the printer 580 and the ground terminal 510.
However, in the past there has been the problem that in some instances electrical continuity is sensed, and ink cartridge consequently determined to be installed, even where terminals 510–560 and contact pins 570 are not in contact due to misalignment of the circuit board 500, etc. A resulting problem in such instances is that despite the determination that the ink cartridge is installed, the data stored in the storage device cannot be read.